Three-dimensional printing-assisted patient-specific titanium cage-augmented Masquelet reconstruction for chronic calcaneal osteomyelitis: a retrospective comparative study with minimum 5-year follow-up

Background Reconstruction of chronic calcaneal osteomyelitis remains challenging because treatment must eradicate infection while restoring a durable weight-bearing hindfoot. This study compared 5- to 8-year outcomes of Masquelet reconstruction augmented with a patient-specific titanium cage shaped using a three-dimensional-printed mold versus conventional graft-only Masquelet reconstruction. Methods This single-center retrospective comparative cohort study included 47 patients treated between January 2017 and January 2020. Twenty-two patients underwent Masquelet reconstruction augmented with a patient-specific titanium cage shaped using a three-dimensional-printed mold, and 25 underwent conventional graft-only Masquelet reconstruction. All patients received two-stage treatment consisting of radical debridement and antibiotic-loaded cement spacer placement, followed by defect reconstruction after infection control. The final-follow-up American Orthopaedic Foot and Ankle Society score was designated post hoc as the principal functional outcome for the reporting hierarchy. The Maryland Foot Score, recovery-related and radiographic outcomes, perioperative variables, and complications were considered secondary or exploratory outcomes. No adjustment for multiple comparisons was applied. Minimum follow-up was 5 years. Results At a mean follow-up of 6.1 years (range, 5–8 years), the intervention group had higher final American Orthopaedic Foot and Ankle Society scores (99.04 ± 1.66 vs. 95.0 ± 3.42; P < 0.01) and Maryland Foot Scores (98.45 ± 2.03 vs. 96.73 ± 2.09; P < 0.01). Although Stage II operative time was longer in the intervention group ( P = 0.01), earlier clinical healing, progression to full weight bearing, and first documented radiographic trabecular incorporation were observed ( P = 0.01, P < 0.01, and P < 0.01, respectively). Calcaneal tuberosity displacement with Achilles tendon contracture occurred in 2 of 22 intervention patients and 7 of 25 control patients, although the difference was not statistically significant. Peri-implant bone resorption was documented in 8 of 22 intervention patients (36.4%), all of whom subsequently underwent elective cage removal after confirmation of osseous union. Conclusion Three-dimensional printing-assisted patient-specific cage–augmented reconstruction was associated with earlier recovery-related outcomes and slightly higher observed functional scores at 5–8 years in selected patients. However, nonrandom treatment allocation, residual confounding, and potential ceiling effects preclude conclusions regarding clinically meaningful superiority; prospective comparative studies are required.